B-8 Reference Guide5. Determine the host addressesFinally, combine your subnet numbers with your host numbers todetermine the actual IP addresses you may use for your 25 hosts.The first three bytes of the address will always be 199.14.17, asassigned to you by InterNIC. The final byte will be the sum of thesubnet number and the host number. The following table shows theranges of IP addresses you can choose from when you configureeach host.Example: Working with a Class C subnetSuppose that your organization has a site with only 10 hosts, andno plans to add any new hosts. You don’t need a full Class Caddress for this site. Many ISPs offer Internet access with only aportion of a full Internet address.For example, you may obtain the Class C address 199.14.17.48,with the mask 255.255.255.240. From the previous example, youcan see that this gives you 14 host addresses to distribute to thehosts at your site. In effect, your existing network of 10 hosts is asubnet of the ISP’s network. Since the Class C address has alreadybeen reduced to subnets, you cannot further subnet your networkwithout the risk of creating network routing problems (since youSubnetlocationSubnetnumberSmallesthostnumberLargesthostnumberSmallestcombinedtotalLargestcombinedtotalIP address range3rd floor 32 1 30 33 62 199.14.17.33 to199.14.17.624th floor 64 1 30 65 94 199.14.17.65 to199.14.17.945th floor 96 1 30 97 126 199.14.17.97 to199.14.17.126
